Introduction:
Inflection of Klotho expression through aerobic exercise training represents an interesting relationship that may contribute to the explanation of the antiaging effects of long-lasting aerobic activity. The purpose of this review was to synthesize the literature on life expectancy in relation to physical activity.

Methods:
To identify all relevant articles about cohort studies investigating the life expectancy, a systematic literature search was conducted in the electronic bibliographical database PubMed.

Results:
All studies reported a higher life expectancy in physically active subjects, ranging from 0.43 to 6.9 additional years (mean ± one standard deviation, men: 2.9 ± 1.3 years, women: 3.9 ± 1.8 years). Eleven studies considered confounding factors that could affect life expectancy, such as body mass index, blood pressure, diabetes mellitus, dyslipidemia, cardiovascular and lung diseases, cancer, smoking, or alcohol consumption. The additional life expectancy in physically active compared to inactive persons in these studies ranged between 0.43 and 4.21 years (2.7 ± 1.1 years). The physically most active groups, included in the estimations of life expectancy, participated in moderate to high leisure time or leisure time and all-day activities. Physical activity during leisure time seems to increase life expectancy more effectively than total physical activity (all-day or leisure time activity altogether): 3.4 added years due to total activities and 4.7 added years (median values) due to leisure time activities in women, 1.9 and 3.9 added years, respectively, in men.

Conclusions:
Acute aerobic exercise significantly increased the circulating Klotho levels, suggesting that long-lasting aerobic training may be appropriate for mechanistically probing the role of physical activity on s-Klotho expression.